The objective of these studies is to test a computerized model of bladder cancer and evaluate its applicability for analyzing problems related to this disease. The model is based on the dynamics of progression along the course of the disease. During the current project period, emphasis has been placed on the calibration and testing of the model using clinical data obtained from the National Bladder Cancer Collaborative Group A (NBCCGA). At the present time, potential cancer screening strategies for asymptomatic populations are being evaluated for their impact on bladder cancer morbidity and mortality using the model. During the coming year, it is proposed that similar model-based assessments of the relative effects of various therapy strategies be undertaken. Members of the NBCCGA and of the Bladder Cancer Subcommittee will serve as consultants to these studies.